An inflatable vehicle occupant protection device, such as an air bag, is inflated when a vehicle experiences a crash. Inflation fluid is then directed to flow from an inflator into the air bag to inflate the air bag. When the air bag is inflated, it extends into the vehicle occupant compartment to protect an occupant of the vehicle from a forceful impact with parts of the vehicle as a result of the crash.
In certain vehicle installations, an air bag is inflated when a vehicle experiences a side impact crash, such as a crash in which an impact is directed against a door at the side of the vehicle. A side impact crash can cause the door to intrude toward the middle of the vehicle. The air bag is inflated into the vehicle occupant compartment between the door and an occupant of a seat adjacent to the door. The inflated air bag can then protect the occupant from a forceful impact with the door.
An air bag and an inflator are typically installed in a vehicle as parts of an air bag module. The module is an assembly of parts that are interconnected separately from the vehicle. For a side impact installation, the module may be mounted on the frame of the seat or on a structural panel in the adjacent door. If the module is mounted on the frame of the seat, the inflating air bag emerges from the seat and moves into the vehicle occupant compartment by breaking through a seat cushion that covers the frame. If the module is mounted on a structural panel in the door, the inflating air bag emerges from the door and moves into the vehicle occupant compartment by breaking through a trim panel that covers the structural panel. A door-mounted module may alternatively include a rupturable cover which extends across an opening in the trim panel. The module cover closes the opening in the trim panel effectively as a rupturable portion of the trim panel.